A phased array antenna typically comprises multiple antenna elements, whose outputs are processed and combined to produce an output Radio Frequency (RF) signal. Various methods and devices for processing signals in phased array antennas are known in the art. For example, U.S. Pat. No. 6,556,168, whose disclosure is incorporated herein by reference, describes a phased array antenna having a multilayered structure in which a number of radiating elements, a phase shift unit and a distribution/synthesis unit are formed on different layers.
U.S. Pat. No. 4,490,721, whose disclosure is incorporated herein by reference, describes a Monolithic Microwave Integrated Circuit (MMIC) that includes an integral array antenna. The system includes radiating elements, a feed network, a phasing network, active and/or passive semiconductor devices, digital logic interface circuits and a microcomputer controller simultaneously incorporated on a single semi-insulating Gallium-Arsenide (GaAs) substrate by means of a controlled fabrication process sequence.
U.S. Patent Application Publication 2003/0107517, whose disclosure is incorporated herein by reference, describes an antenna beam control system, in which four antenna elements are connected to first signal processing circuits, to which phase shift circuits are connected. Output signals from the phase shift circuits are combined by a combiner, a combined signal is processed by a second signal processing circuit, and phase shift amounts in the phase shift circuits are controlled in accordance with strength information of the signal processed in the second signal processing circuit. In some embodiments, the antenna beam control system is realized by an Integrated Circuit (IC) chip.
PCT International Publication WO 2005/050776, whose disclosure is incorporated herein by reference, describes a phased array receiver, which is fabricated on a single silicon substrate. The phased array receiver receives a 24 GHz signal and includes eight elements formed in a SiGe BiCMOS technology. The receiver utilizes a heterodyne topology, and signal combining is performed at an IF of 4.8 GHz.